As medical device technologies continue to evolve, neurostimulator devices have gained much popularity in the medical field. Neurostimulator devices are typically battery-powered devices that are designed to deliver electrical stimulation to a patient. Through proper electrical stimulation, the neurostimulator devices can provide pain relief for patients.
A typical neurostimulator device may include one or more integrated circuit chips on which the control circuitry and neurostimulation circuitry are built. The neurostimulator device may also include a plurality of channels. These channels include respective electrodes that are in contact with different tissue areas of a patient's body. Controlled by the control circuitry, the electrodes are each capable of delivering electrical stimulation to their respective target contact areas. Thus, the patient can use the neurostimulator device to stimulate areas in a localized manner.
Typically, neurostimulator devices have the ability to measure the impedance between channels to monitor the health and operation of the lead wires and electrodes, as well as the impedance of the tissue. Usually, existing neurostimulator devices have to be put into a diagnostic mode in order to make impedance measurements. While in this diagnostic mode, active stimulation is suspended. Measuring impedance in the diagnostic mode may cause several problems, which include delayed detection of component failure, pain or discomfort to the patient, or inaccurate measurement results.
Therefore, while existing neurostimulator devices have been generally adequate for their intended purposes, they have not been entirely satisfactory in every aspect.